Organic light emitting display device and a method of manufacturing thereof

ABSTRACT

Discloses is an organic light emitting display device including a first substrate divided into a pixel region and a non-pixel region. An organic light emitting element includes a first electrode, an organic thin film layer and a second electrode formed in the pixel region. A scan driver and a metal film corresponding to a region of the scan driver are formed in the non-pixel region. A second substrate is spaced apart from the pixel region and the non-pixel region of the first substrate. A frit is formed along an edge of a non-pixel region of the second substrate, wherein the frit is formed so that it can be overlapped with an active area of the scan driver formed in the non-pixel region.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No.10-2006-0008768, filed on Jan. 27, 2006, in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein byreference in its entirety. This application is related to andincorporates herein by reference the entire contents of the followingconcurrently filed application:

Filing Application Title Atty. Docket No. Date No. ORGANIC LIGHTEMITTING SDISHN.050AUS DISPLAY DEVICE AND A METHOD OF MANUFACTURINGTHEREOF

BACKGROUND

1. Field

The invention relates to an organic light emitting display device and amethod of manufacturing the same.

2. Discussion of the Related Technology

Generally, an organic light emitting display device is composed of asubstrate providing a pixel region and a non-pixel region; a containeror a substrate arranged to face the substrate for its encapsulation andcoalesced into the substrate using a sealant such as epoxy.

A plurality of light emitting elements connected between scan lines anddata lines in a matrix arrangement are formed in a pixel region of thesubstrate. The light emitting elements are composed of an anodeelectrode; a cathode electrode; and an organic thin film layer formedbetween the anode electrode and the cathode electrode. The organic layercan include a hole transport layer, an organic emitting layer and anelectron transport layer.

However, the light emitting element, configured as described above, issusceptible to hydrogen or oxygen since it includes organic substances.The elements are also easily oxidized by moisture in the air since acathode electrode is generally formed of metallic materials andtherefore its electrical and light-emission properties are subject todeterioration. Accordingly, moisture penetrated from the outside shouldbe excluded and removed in order to inhibit this deterioration byloading a container manufactured in a form of a metallic can or cup, anda substrate such as glass, plastic, etc. with a moisture absorbent in apowdery form or adhering the moisture absorbent, in a form of film, tothe container.

However, the above method for loading a container with a moistureabsorbent in a powdery form has disadvantages in that its process iscomplex, the material and manufacturing cost is expensive, a resultingdisplay device is thick, and it is difficult to apply to a top emissiondisplay. In addition, the above method for adhering the moistureabsorbent, in a form of film, to the container has disadvantages in thatit is difficult to remove moisture and its mass-production is difficultdue to low durability and reliability. The above is simply to describegenerally the field of organic light emitting displays and is not anadmission of prior art.

In order to solve the problems, various methods for encapsulating alight emitting element by forming a side wall with a frit have beendisclosed.

International Patent application No. PCT/KR2002/000994 (May 24, 2002)discloses an encapsulation container having a side wall formed of aglass frit; and a method of manufacturing the same.

Korean Patent Publication No. 2001-0084380 (Sep. 6, 2001) discloses amethod for encapsulating a frit frame using a laser.

Korean Patent Publication No. 2002-0051153 (Jun. 28, 2002) discloses apackaging method for encapsulating an upper substrate and a lowersubstrate with a frit using a laser.

SUMMARY OF CERTAIN INVENTIVE ASPECTS

An aspect of the invention provides an organic light emitting device,which may comprise: a first substrate defining a pixel region and anon-pixel region; an array of organic light emitting pixels formed overthe pixel region of the first substrate; a second substrate placed overthe first substrate, the array being interposed between the first andsecond substrates; a frit seal comprising a plurality of elongatedsegments interposed between the first and second substrates, theplurality of elongated segments in combination surrounding the arraysuch that the array is encapsulated by the first substrate, the secondsubstrate and the frit seal, the plurality of elongated segmentscomprising a first elongated segment elongated generally in a firstdirection; and a scan driver formed over the non-pixel region of thefirst substrate, wherein the scan driver overlaps with the firstelongated segment when viewed in a second direction from the first orsecond substrate, wherein the shortest distance between the first andsecond substrates is defined in the second direction.

In the foregoing device, the first elongated segment may substantiallyeclipse the scan driver. The scan driver may substantially eclipse thefirst elongated segment. The frit may not overlap the scan driver in itsentirety. The scan driver may extend generally in the first directionparallel to the first elongated segment. The first elongated segment mayoverlap a portion of the scan driver facing the array. The portion maybe elongated generally in the first direction. The portion may have awidth defined in a third direction perpendicular to the first and seconddirections, and wherein the width may be from about 0.05 mm to about 1.0mm. The scan driver may have a width defined in a third directionperpendicular to the first and second directions, wherein the width maybe from about 0.2 mm to about 1.5 mm. The scan driver comprises a wiringarea, and wherein the first elongated segment may overlap with thewiring area when viewed in the second direction. The scan driver maycomprise an active area, and wherein the first elongated segment mayoverlap with the active area when viewed in the second direction.

Still in the foregoing method, the device may further comprise anelectrically conductive layer formed between the first elongated segmentand the scan driver. The array may comprise an anode, and wherein theelectrically conductive layer may be deposited simultaneously with theanode. The electrically conductive layer may be reflective with respectto a laser beam or infrared beam. The device may further comprise aplanarization layer formed between the first substrate and the frit, andwherein the scan driver may be substantially buried in the planarizationlayer. The scan driver may comprise an integrated circuit comprising athin film transistor. The frit seal may comprise one or more materialsselected from the group consisting of magnesium oxide (MgO), calciumoxide (CaO), barium oxide (BaO), lithium oxide (Li₂O), sodium oxide(Na₂O), potassium oxide (K₂O), boron oxide (B₂O₃), vanadium oxide(V₂O₅), zinc oxide (ZnO), tellurium oxide (TeO₂), aluminum oxide(Al₂O₃), silicon dioxide (SiO₂), lead oxide (PbO), tin oxide (SnO),phosphorous oxide (P₂O₅), ruthenium oxide (Ru₂O), rubidium oxide (Rb₂O),rhodium oxide (Rh₂O), ferrite oxide (Fe₂O₃), copper oxide (CuO),titanium oxide (TiO₂), tungsten oxide (WO₃), bismuth oxide (Bi₂O₃),antimony oxide (Sb₂O₃), lead-borate glass, tin-phosphate glass, vanadateglass, and borosilicate.

Another aspect of the invention provides a method of making an organiclight emitting device, which may comprise: providing a first substratedefining a pixel region and a non-pixel region; forming an array oforganic light emitting pixels over the pixel region of the firstsubstrate; forming a scan driver over the non-pixel region of the firstsubstrate; arranging a second substrate over the first substrate suchthat the array being interposed between the first and second substrates;interposing a frit comprising a plurality of elongated segments betweenthe first substrate and second substrate, the plurality of elongatedsegments in combination surrounding the array, and the plurality ofelongated segments comprising a first elongated segment elongatedgenerally in a first direction; and wherein the scan driver overlapswith the first elongated segment when viewed in a second direction fromthe first or second substrate, wherein the shortest distance between thefirst and second substrates is defined in the second direction. In theforegoing method, the first elongated segment may substantially eclipsethe scan driver. An electrically conductive layer may be interposedbetween the first elongated segment and the scan driver.

In a method for encapsulating a light emitting element with a frit usedherein, a sealing substrate coated with the frit can be coalesced intothe substrate in which the light emitting element is formed, and thenthe frit can be melted and adhered to the substrate by irradiating alaser in the back surface of the sealing substrate.

Accordingly, aspects of the invention provide an organic light emittingdisplay device capable of reducing a dead space by forming a frit sothat the frit can be overlapped with a scan driver and inhibiting thescan driver from being damaged upon irradiating a laser to the frit byforming a metal film in a region corresponding to the scan driver; and amethod of manufacturing the same.

The foregoing and/or other aspects of the invention provides an organiclight emitting display device including a first substrate defining apixel region and a non-pixel region, wherein an organic light emittingelement composed of a first electrode, an organic thin film layer and asecond electrode is formed in the pixel region and a scan driver and ametal film corresponding to a region of the scan driver are formed inthe non-pixel region; a second substrate sealed spaced apart from thepixel region and the non-pixel region of the first substrate; and a fritformed along an edge of a non-pixel region of the second substrate,wherein the frit is formed so that it can be overlapped with an activearea of the scan driver formed in the non-pixel region.

The foregoing and/or another aspects of the invention provides a methodfor manufacturing an organic light emitting display device, includingsteps of providing an organic light emitting element composed of a firstelectrode, an organic thin film layer and a second electrode in thepixel region of the first substrate divided into a pixel region and anon-pixel region and providing a scan driver and a metal filmcorresponding to a region of the scan driver in the non-pixel region;forming a frit along an edge of a region, which corresponds to the scandriver of the non-pixel region of the first substrate, in a secondsubstrate sealed spaced apart a predetermined distance from the firstsubstrate; arranging the second substrate on the first substrate so thatthe frit formed in the second substrate can be overlapped with an activearea of the scan driver which is a non-pixel region of the firstsubstrate; and adhering the first substrate to the second substrate byirradiating a laser beam to the frit in the back surface of the secondsubstrate.

Further embodiments provide a method of making an organic light emittingdevice, the method comprising providing an unfinished device comprisinga first substrate, an array of organic light emitting pixels formed overthe first substrate, and an electrically conductive line formed over thefirst substrate, further providing a second substrate, interposing afrit between the first and second substrates such that the array isinterposed between the first and second substrates and such that thefrit surrounds the array, arranging the second substrate on the firstsubstrate so that the frit overlaps with an active area of a scan driverin the non-pixel region of the first substrate, and melting andresolidifying at least part of the frit so as to interconnect theunfinished device and the second substrate via the frit.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects and advantages of the invention will becomeapparent and more readily appreciated from the following description ofthe embodiments, taken in conjunction with the accompanying drawings ofwhich:

FIG. 1 is a plan view showing one embodiment of an organic lightemitting display device;

FIG. 2 is a cross-sectional view taken from a line I-I′ of the FIG. 1;

FIG. 3 is a plane view showing one embodiment of an organic lightemitting display device;

FIG. 4 is a cross-sectional view taken from a line II-II′ of the FIG. 3;and

FIG. 5 is a cross-sectional view taken from a line III-III′ of the FIG.3.

FIG. 6 is a schematic exploded view of a passive matrix type organiclight emitting display device in accordance with one embodiment.

FIG. 7 is a schematic exploded view of an active matrix type organiclight emitting display device in accordance with one embodiment.

FIG. 8 is a schematic top plan view of an organic light emitting displayin accordance with one embodiment.

FIG. 9 is a cross-sectional view of the organic light emitting displayof FIG. 8, taken along the line 9-9.

FIG. 10 is a schematic perspective view illustrating mass production oforganic light emitting devices in accordance with one embodiment.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

Hereinafter, embodiments according to the invention will be described indetail with reference to the accompanying drawings. Therefore, thedescription proposed herein is just one example for the purpose ofillustrations only, not intended to limit the scope of the invention, soit should be understood that other equivalents and modifications couldbe made thereto without departing from the spirit and scope of theinvention, as apparent to those skilled in the art.

An organic light emitting display (OLED) is a display device comprisingan array of organic light emitting diodes. Organic light emitting diodesare solid state devices which include an organic material and areadapted to generate and emit light when appropriate electricalpotentials are applied.

OLEDs can be generally grouped into two basic types dependent on thearrangement with which the stimulating electrical current is provided.FIG. 6 schematically illustrates an exploded view of a simplifiedstructure of a passive matrix type OLED 1000. FIG. 7 schematicallyillustrates a simplified structure of an active matrix type OLED 1001.In both configurations, the OLED 1000, 1001 includes OLED pixels builtover a substrate 1002, and the OLED pixels include an anode 1004, acathode 1006 and an organic layer 1010. When an appropriate electricalcurrent is applied to the anode 1004, electric current flows through thepixels and visible light is emitted from the organic layer.

Referring to FIG. 6, the passive matrix OLED (PMOLED) design includeselongate strips of anode 1004 arranged generally perpendicular toelongate strips of cathode 1006 with organic layers interposedtherebetween. The intersections of the strips of cathode 1006 and anode1004 define individual OLED pixels where light is generated and emittedupon appropriate excitation of the corresponding strips of anode 1004and cathode 1006. PMOLEDs provide the advantage of relatively simplefabrication.

Referring to FIG. 7, the active matrix OLED (AMOLED) includes drivingcircuits 1012 arranged between the substrate 1002 and an array of OLEDpixels. An individual pixel of AMOLEDs is defined between the commoncathode 1006 and an anode 1004, which is electrically isolated fromother anodes. Each driving circuit 1012 is coupled with an anode 1004 ofthe OLED pixels and further coupled with a data line 1016 and a scanline 1018. In embodiments, the scan lines 1018 supply scan signals thatselect rows of the driving circuits, and the data lines 1016 supply datasignals for particular driving circuits. The data signals and scansignals stimulate the local driving circuits 1012, which excite theanodes 1004 so as to emit light from their corresponding pixels.

In the illustrated AMOLED, the local driving circuits 1012, the datalines 1016 and scan lines 1018 are buried in a planarization layer 1014,which is interposed between the pixel array and the substrate 1002. Theplanarization layer 1014 provides a planar top surface on which theorganic light emitting pixel array is formed. The planarization layer1014 may be formed of organic or inorganic materials, and formed of twoor more layers although shown as a single layer. The local drivingcircuits 1012 are typically formed with thin film transistors (TFT) andarranged in a grid or array under the OLED pixel array. The localdriving circuits 1012 may be at least partly made of organic materials,including organic TFT. AMOLEDs have the advantage of fast response timeimproving their desirability for use in displaying data signals. Also,AMOLEDs have the advantages of consuming less power than passive matrixOLEDs.

Referring to common features of the PMOLED and AMOLED designs, thesubstrate 1002 provides structural support for the OLED pixels andcircuits. In various embodiments, the substrate 1002 can comprise rigidor flexible materials as well as opaque or transparent materials, suchas plastic, glass, and/or foil. As noted above, each OLED pixel or diodeis formed with the anode 1004, cathode 1006 and organic layer 1010interposed therebetween. When an appropriate electrical current isapplied to the anode 1004, the cathode 1006 injects electrons and theanode 1004 injects holes. In certain embodiments, the anode 1004 andcathode 1006 are inverted; i.e., the cathode is formed on the substrate1002 and the anode is opposingly arranged.

Interposed between the cathode 1006 and anode 1004 are one or moreorganic layers. More specifically, at least one emissive or lightemitting layer is interposed between the cathode 1006 and anode 1004.The light emitting layer may comprise one or more light emitting organiccompounds. Typically, the light emitting layer is configured to emitvisible light in a single color such as blue, green, red or white. Inthe illustrated embodiment, one organic layer 1010 is formed between thecathode 1006 and anode 1004 and acts as a light emitting layer.Additional layers, which can be formed between the anode 1004 andcathode 1006, can include a hole transporting layer, a hole injectionlayer, an electron transporting layer and an electron injection layer.

Hole transporting and/or injection layers can be interposed between thelight emitting layer 1010 and the anode 1004. Electron transportingand/or injecting layers can be interposed between the cathode 1006 andthe light emitting layer 1010. The electron injection layer facilitatesinjection of electrons from the cathode 1006 toward the light emittinglayer 1010 by reducing the work function for injecting electrons fromthe cathode 1006. Similarly, the hole injection layer facilitatesinjection of holes from the anode 1004 toward the light emitting layer1010. The hole and electron transporting layers facilitate movement ofthe carriers injected from the respective electrodes toward the lightemitting layer.

In some embodiments, a single layer may serve both electron injectionand transportation functions or both hole injection and transportationfunctions. In some embodiments, one or more of these layers are lacking.In some embodiments, one or more organic layers are doped with one ormore materials that help injection and/or transportation of thecarriers. In embodiments where only one organic layer is formed betweenthe cathode and anode, the organic layer may include not only an organiclight emitting compound but also certain functional materials that helpinjection or transportation of carriers within that layer.

There are numerous organic materials that have been developed for use inthese layers including the light emitting layer. Also, numerous otherorganic materials for use in these layers are being developed. In someembodiments, these organic materials may be macromolecules includingoligomers and polymers. In some embodiments, the organic materials forthese layers may be relatively small molecules. The skilled artisan willbe able to select appropriate materials for each of these layers in viewof the desired functions of the individual layers and the materials forthe neighboring layers in particular designs.

In operation, an electrical circuit provides appropriate potentialbetween the cathode 1006 and anode 1004. This results in an electricalcurrent flowing from the anode 1004 to the cathode 1006 via theinterposed organic layer(s). In one embodiment, the cathode 1006provides electrons to the adjacent organic layer 1010. The anode 1004injects holes to the organic layer 101.0. The holes and electronsrecombine in the organic layer 1010 and generate energy particles called“excitons.” The excitons transfer their energy to the organic lightemitting material in the organic layer 1010, and the energy is used toemit visible light from the organic light emitting material. Thespectral characteristics of light generated and emitted by the OLED1000, 1001 depend on the nature and composition of organic molecules inthe organic layer(s). The composition of the one or more organic layerscan be selected to suit the needs of a particular application by one ofordinary skill in the art.

OLED devices can also be categorized based on the direction of the lightemission. In one type referred to as “top emission” type, OLED devicesemit light and display images through the cathode or top electrode 1006.In these embodiments, the cathode 1006 is made of a material transparentor at least partially transparent with respect to visible light. Incertain embodiments, to avoid losing any light that can pass through theanode or bottom electrode 1004, the anode may be made of a materialsubstantially reflective of the visible light. A second type of OLEDdevices emits light through the anode or bottom electrode 1004 and iscalled “bottom emission” type. In the bottom emission type OLED devices,the anode 1004 is made of a material which is at least partiallytransparent with respect to visible light. Often, in bottom emissiontype OLED devices, the cathode 1006 is made of a material substantiallyreflective of the visible light. A third type of OLED devices emitslight in two directions, e.g. through both anode 1004 and cathode 1006.Depending upon the direction(s) of the light emission, the substrate maybe formed of a material which is transparent, opaque or reflective ofvisible light.

In many embodiments, an OLED pixel array 1021 comprising a plurality oforganic light emitting pixels is arranged over a substrate 1002 as shownin FIG. 8. In embodiments, the pixels in the array 1021 are controlledto be turned on and off by a driving circuit (not shown), and theplurality of the pixels as a whole displays information or image on thearray 1021. In certain embodiments, the OLED pixel array 1021 isarranged with respect to other components, such as drive and controlelectronics to define a display region and a non-display region. Inthese embodiments, the display region refers to the area of thesubstrate 1002 where OLED pixel array 1021 is formed. The non-displayregion refers to the remaining areas of the substrate 1002. Inembodiments, the non-display region can contain logic and/or powersupply circuitry. It will be understood that there will be at leastportions of control/drive circuit elements arranged within the displayregion. For example, in PMOLEDs, conductive components will extend intothe display region to provide appropriate potential to the anode andcathodes. In AMOLEDs, local driving circuits and data/scan lines coupledwith the driving circuits will extend into the display region to driveand control the individual pixels of the AMOLEDs.

One design and fabrication consideration in OLED devices is that certainorganic material layers of OLED devices can suffer damage or accelerateddeterioration from exposure to water, oxygen or other harmful gases.Accordingly, it is generally understood that OLED devices be sealed orencapsulated to inhibit exposure to moisture and oxygen or other harmfulgases found in a manufacturing or operational environment. FIG. 9schematically illustrates a cross-section of an encapsulated OLED device1011 having a layout of FIG. 8 and taken along the line 9-9 of FIG. 8.In this embodiment, a generally planar top plate or substrate 1061engages with a seal 1071 which further engages with a bottom plate orsubstrate 1002 to enclose or encapsulate the OLED pixel array 1021. Inother embodiments, one or more layers are formed on the top plate 1061or bottom plate 1002, and the seal 1071 is coupled with the bottom ortop substrate 1002, 1061 via such a layer. In the illustratedembodiment, the seal 1071 extends along the periphery of the OLED pixelarray 1021 or the bottom or top plate 1002, 1061.

In embodiments, the seal 1071 is made of a frit material as will befurther discussed below. In various embodiments, the top and bottomplates 1061, 1002 comprise materials such as plastics, glass and/ormetal foils which can provide a barrier to passage of oxygen and/orwater to thereby protect the OLED pixel array 1021 from exposure tothese substances. In embodiments, at least one of the top plate 1061 andthe bottom plate 1002 are formed of a substantially transparentmaterial.

To lengthen the life time of OLED devices 1011, it is generally desiredthat seal 1071 and the top and bottom plates 1061, 1002 provide asubstantially non-permeable seal to oxygen and water vapor and provide asubstantially hermetically enclosed space 1081. In certain applications,it is indicated that the seal 1071 of a frit material in combinationwith the top and bottom plates 1061, 1002 provide a barrier to oxygen ofless than approximately 10⁻³ cc/m²-day and to water of less than 10⁻⁶g/m²-day. Given that some oxygen and moisture can permeate into theenclosed space 1081, in some embodiments, a material that can take upoxygen and/or moisture is formed within the enclosed space 1081.

The seal 1071 has a width W, which is its thickness in a directionparallel to a surface of the top or bottom substrate 1061, 1002 as shownin FIG. 9. The width varies among embodiments and ranges from about 300μm to about 3000 μm, optionally from about 500 μm to about 1500 μm.Also, the width may vary at different positions of the seal 1071. Insome embodiments, the width of the seal 1071 may be the largest wherethe seal 1071 contacts one of the bottom and top substrate 1002, 1061 ora layer formed thereon. The width may be the smallest where the seal1071 contacts the other. The width variation in a single cross-sectionof the seal 1071 relates to the cross-sectional shape of the seal 1071and other design parameters.

The seal 1071 has a height H, which is its thickness in a directionperpendicular to a surface of the top or bottom substrate 1061, 1002 asshown in FIG. 9. The height varies among embodiments and ranges fromabout 2 μm to about 30 μm, optionally from about 10 μm to about 15 μm.Generally, the height does not significantly vary at different positionsof the seal 1071. However, in certain embodiments, the height of theseal 1071 may vary at different positions thereof.

In the illustrated embodiment, the seal 1071 has a generally rectangularcross-section. In other embodiments, however, the seal 1071 can haveother various cross-sectional shapes such as a generally squarecross-section, a generally trapezoidal cross-section, a cross-sectionwith one or more rounded edges, or other configuration as indicated bythe needs of a given application. To improve hermeticity, it isgenerally desired to increase the interfacial area where the seal 1071directly contacts the bottom or top substrate 1002, 1061 or a layerformed thereon. In some embodiments, the shape of the seal can bedesigned such that the interfacial area can be increased.

The seal 1071 can be arranged immediately adjacent the OLED array 1021,and in other embodiments, the seal 1071 is spaced some distance from theOLED array 1021. In certain embodiment, the seal 1071 comprisesgenerally linear segments that are connected together to surround theOLED array 1021. Such linear segments of the seal 1071 can extend, incertain embodiments, generally parallel to respective boundaries of theOLED array 1021. In other embodiment, one or more of the linear segmentsof the seal 1071 are arranged in a non-parallel relationship withrespective boundaries of the OLED array 1021. In yet other embodiments,at least part of the seal 1071 extends between the top plate 1061 andbottom plate 1002 in a curvilinear manner.

As noted above, in certain embodiments, the seal 1071 is formed using afrit material or simply “frit” or glass frit,” which includes fine glassparticles. The frit particles includes one or more of magnesium oxide(MgO), calcium oxide (CaO), barium oxide (BaO), lithium oxide (Li₂O),sodium oxide (Na₂O), potassium oxide (K₂O), boron oxide (B₂O₃), vanadiumoxide (V₂O₅), zinc oxide (ZnO), tellurium oxide (TeO₂), aluminum oxide(Al₂O₃), silicon dioxide (SiO₂), lead oxide (PbO), tin oxide (SnO),phosphorous oxide (P₂O₅), ruthenium oxide (Ru₂O), rubidium oxide (Rb₂O),rhodium oxide (Rh₂O), ferrite oxide (Fe₂O₃), copper oxide (CuO),titanium oxide (TiO₂), tungsten oxide (WO₃), bismuth oxide (Bi₂O₃),antimony oxide (Sb₂O₃), lead-borate glass, tin-phosphate glass, vanadateglass, and borosilicate, etc. In embodiments, these particles range insize from about 2 μm to about 30 μm, optionally about 5 μm to about 10μm, although not limited only thereto. The particles can be as large asabout the distance between the top and bottom substrates 1061, 1002 orany layers formed on these substrates where the frit seal 1071 contacts.

The frit material used to form the seal 1071 can also include one ormore filler or additive materials. The filler or additive materials canbe provided to adjust an overall thermal expansion characteristic of theseal 1071 and/or to adjust the absorption characteristics of the seal1071 for selected frequencies of incident radiant energy. The filler oradditive material(s) can also include inversion and/or additive fillersto adjust a coefficient of thermal expansion of the frit. For example,the filler or additive materials can include transition metals, such aschromium (Cr), iron (Fe), manganese (Mn), cobalt (Co), copper (Cu),and/or vanadium. Additional materials for the filler or additivesinclude ZnSiO₄, PbTiO₃, ZrO₂, eucryptite.

In embodiments, a frit material as a dry composition contains glassparticles from about 20 to 90 about wt %, and the remaining includesfillers and/or additives. In some embodiments, the frit paste containsabout 10-30 wt % organic materials and about 70-90% inorganic materials.In some embodiments, the frit paste contains about 20 wt % organicmaterials and about 80 wt % inorganic materials. In some embodiments,the organic materials may include about 0-30 wt % binder(s) and about70-100 wt % solvent(s). In some embodiments, about 10 wt % is binder(s)and about 90 wt % is solvent(s) among the organic materials. In someembodiments, the inorganic materials may include about 0-10 wt %additives, about 20-40 wt % fillers and about 50-80 wt % glass powder.In some embodiments, about 0-5 wt % is additive(s), about 25-30 wt % isfiller(s) and about 65-75 wt % is the glass powder among the inorganicmaterials.

In forming a frit seal, a liquid material is added to the dry fritmaterial to form a frit paste. Any organic or inorganic solvent with orwithout additives can be used as the liquid material. In embodiments,the solvent includes one or more organic compounds. For example,applicable organic compounds are ethyl cellulose, nitro cellulose,hydroxylpropyl cellulose, butyl carbitol acetate, terpineol, butylcellusolve, acrylate compounds. Then, the thus formed frit paste can beapplied to form a shape of the seal 1071 on the top and/or bottom plate1061, 1002.

In one exemplary embodiment, a shape of the seal 1071 is initiallyformed from the frit paste and interposed between the top plate 1061 andthe bottom plate 1002. The seal 1071 can in certain embodiments bepre-cured or pre-sintered to one of the top plate and bottom plate 1061,1002. Following assembly of the top plate 1061 and the bottom plate 1002with the seal 1071 interposed therebetween, portions of the seal 1071are selectively heated such that the frit material forming the seal 1071at least partially melts. The seal 1071 is then allowed to resolidify toform a secure joint between the top plate 1061 and the bottom plate 1002to thereby inhibit exposure of the enclosed OLED pixel array 1021 tooxygen or water.

In embodiments, the selective heating of the frit seal is carried out byirradiation of light, such as a laser or directed infrared lamp. Aspreviously noted, the frit material forming the seal 1071 can becombined with one or more additives or filler such as species selectedfor improved absorption of the irradiated light to facilitate heatingand melting of the frit material to form the seal 1071.

In some embodiments, OLED devices 1011 are mass produced. In anembodiment illustrated in FIG. 10, a plurality of separate OLED arrays1021 is formed on a common bottom substrate 1101. In the illustratedembodiment, each OLED array 1021 is surrounded by a shaped frit to formthe seal 1071. In embodiments, common top substrate (not shown) isplaced over the common bottom substrate 1101 and the structures formedthereon such that the OLED arrays 1021 and the shaped frit paste areinterposed between the common bottom substrate 1101 and the common topsubstrate. The OLED arrays 1021 are encapsulated and sealed, such as viathe previously described enclosure process for a single OLED displaydevice. The resulting product includes a plurality of OLED devices kepttogether by the common bottom and top substrates. Then, the resultingproduct is cut into a plurality of pieces, each of which constitutes anOLED device 1011 of FIG. 9. In certain embodiments, the individual OLEDdevices 1011 then further undergo additional packaging operations tofurther improve the sealing formed by the frit seal 1071 and the top andbottom substrates 1061, 1002.

FIG. 1 is a plan view showing an organic light emitting display device.FIG. 2 is a cross-sectional view taken from a line I-I′ of the FIG. 1.

As shown in FIG. 1 and FIG. 2, an organic light emitting display deviceis composed of a deposition substrate 10, an encapsulation substrate 20and a frit 30. The deposition substrate 10 is a substrate including apixel region 11 including at least one organic light emitting element;and a non-pixel region 15 formed in a circumference of the pixel region11, and the encapsulation substrate 20 is adhered against a surface inwhich an organic light emitting element 16 of the deposition substrate10 is formed. Here, drives such as a scan driver 12 and a data driver 13are formed in the non-pixel region 15 of the deposition substrate 10,respectively.

In order to adhere the deposition substrate 10 to the encapsulationsubstrate 20, the frit 30 is applied along edges of the depositionsubstrate 10 and the encapsulation substrate 20, and the frit 30 is alsocured using methods such as irradiation of a laser beam or anultraviolet ray, etc. Here, the frit 30 is applied such that hydrogen,oxygen, moisture, etc. that penetrate between a fine gap are obstructedsince an encapsulating material is formed additionally.

Meanwhile, in one embodiment, the organic light emitting display devicehas a scan driver width (0.4 mm) and a signal line width (0.3 mm) formedin a non-pixel region 15; and a frit width (0.7 mm) 30 formed in aregion of a seal of width (1.5 mm) 14 between the pixel region 11 andthe non-pixel region 15. Here, an active area of the scan driver has awidth of approximately 0.15 mm, and a wiring area of the scan driver hasa width of approximately 0.25 mm.

However, if in the non-pixel region a dead space region is formed in awide range as described above, then the organic light emitting displaydevice has a disadvantage that quality of the products is deteriorateddue to its increase size.

FIG. 3 is a plan view showing one embodiment of an organic lightemitting display device. As shown in FIG. 3, an organic light emittingdisplay device is divided into a pixel region 210 and a non-pixel region220, wherein an organic light emitting element composed of a firstelectrode, an organic thin film layer and a second electrode is formedin the pixel region 210. The non-pixel region 220 includes a firstsubstrate 200 in which a scan driver 410 and a metal film 108 bcorresponding to a region of the scan driver are formed. A secondsubstrate 300 is sealed and spaced apart a predetermined distance fromthe pixel region 210 and the non-pixel region 220 of the first substrate200. A frit 320 is formed in spaced gaps of the non-pixel regions of thefirst substrate 200 and the second substrate 300 and formed so that itcan be overlapped with an active area of a scan driver 410 of the firstsubstrate 200.

The first substrate 200 of the organic light emitting display device isreferred to as a pixel region 210 and a non-pixel region 220 surroundingthe pixel region 210. In the pixel region 210 of the first substrate 200are formed a plurality of organic light emitting elements 100 connectedbetween a scan line 104 b and a data line 106 c in a matrix arrangement.In the non-pixel region 220 of the first substrate 200 are formed a scanline 104 b and a data line 106 c extending from the scan line 104 b andthe data line 106 c of the pixel region 210. A power supply line (notshown) for operating an organic light emitting element 100 and a scandrive unit 410 and a data drive unit 420 for treating signals areprovided from the outside through pads 104 c and 106 d, to supply thesignals to the scan line 104 b and the data line 106 c.

FIG. 4 is a cross-sectional view taken from a line II-II′ in which ametal film and a scan driver are not illustrated. As shown in FIG. 4,the organic light emitting element 100 formed in the pixel region iscomposed of an anode electrode 108 a as a first electrode, a cathodeelectrode 111 as a second electrode, and an organic thin film layer 110formed between the anode electrode 108 a and the cathode electrode 111.The organic thin film layer 110 has a structure in which a holetransport layer, an organic emitting layer and an electron transportlayer are laminated, and may further include a hole injection layer andan electron injection layer. In addition, the organic thin film layer110 may further include a switching transistor for controlling anoperation of the organic light emitting diode 100, and a capacitor forsustaining signals.

Hereinafter, one embodiment of a process of manufacturing an organiclight emitting element 100 will be described in detail, as follows. Abuffer layer 101 is formed on a substrate 200 of a pixel region 210 anda non-pixel region 220. The buffer layer 101 inhibits the substrate 200from being damaged by heat and obstructs ions from being diffused fromthe substrate 200. The buffer layer 101 can be formed of insulationfilms such as a silicon oxide film (SiO₂) and/or a silicon nitride film(SiNx).

A semiconductor layer 102 can be provided with an active layer and beformed in a predetermined region on the buffer layer 101 of the pixelregion 210. A gate insulation film 103 can be formed in the uppersurface of the pixel region 210 including the semiconductor layer 102.

A gate electrode 104 a is formed on the gate insulation film 103 in theupper portion of the semiconductor layer 102. In the pixel region 210 isformed a scan line 104 b connected with the gate electrode 104 a. In thenon-pixel region 220 are formed a scan line 104 b extended from the scanline 104 b of the pixel region 210; and a pad 104 c for receivingsignals from the outside. In one embodiment the gate electrode 104 a,the scan line 104 b and the pad 104 c comprise metals such as molybdenum(Mo), tungsten (W), titanium (Ti), aluminum (Al), etc., alloys thereof,and/or formed with a laminated structure.

An interlayer insulation film 105 is formed on upper surfaces of thepixel region 210 and the non-pixel region 220 which include the gateelectrode 104 a, respectively. The interlayer insulation film 105 andthe gate insulation film 103 are patterned to form a contact hole so asto expose a region of the semiconductor layer 102. Source and drainelectrodes 106 a and 106 b are formed so that they can be connected withthe semiconductor layer 102 through the contact hole. In the pixelregion 210 is formed a data line 106 c connected with the source anddrain electrodes 106 a and 106 b. In the non-pixel region 220 is formeda data line 106 c extended from the data line 106 c of the pixel region210 and a pad 106 d for receiving signals from the outside. The sourceand drain electrodes 106 a and 106 b, the data line 106 c and the pad106 d comprise metals such as molybdenum (Mo), tungsten (W), titanium(Ti), aluminum (Al), etc., alloys thereof, and/or are formed with alaminated structure.

An overcoat 107 is formed on upper surfaces of the pixel region 210 andthe non-pixel region 220 to flatten the surfaces. The overcoat 107 ofthe pixel region 210 is patterned to form a via hole so as to expose aregion of the source or drain electrodes 106 a or 106 b. An anodeelectrode 108 is forced to connect with the source or drain electrodes106 a or 106 b through the via hole.

An organic thin film layer 110 is formed on the overcoat 107 so as toexpose some region of the anode electrode 108 a. An organic thin filmlayer 110 is formed on the exposed anode electrode 108 a and a cathodeelectrode 111 is formed on a pixel definition layer 109 including theorganic thin film layer 110.

A metal film 108 b is formed by depositing metallic materials such asthe anode electrode 108 a onto an overcoat 107 of the non-pixel region220 when forming the anode electrode 108 a. The metal film 108 b isformed to the extent of an active area, a wiring area and a signal linearea of the scan driver to correspond to a region in which the frit 320is formed.

A sealing substrate is formed having a suitable size so that the secondsubstrate 300 can be overlapped with some regions of the pixel region210 and the non-pixel region 220. A substrate composed of transparentmaterials such as glass may be used as the second substrate 300. Incertain embodiments, substrate comprises silicon oxide (SiO₂).

FIG. 5 is a cross-sectional view taken from a line III-III′, in whichthe scan driver is not illustrated. As shown in FIG. 5, a frit 320 forencapsulation is formed along an edge of the second substrate 300corresponding to the non-pixel region 220. Here, the frit 320 has awidth of approximately 0.7 mm, and is formed so that it can beoverlapped with an active area of the scan driver 410.

More specifically, the scan driver 410 in the non-pixel region 220includes an active area, a scan driver wiring area and a signal line,and therefore the scan driver 410 has a width of approximately 0.7 mm.The active area of the scan driver has a width of approximately 0.15 mm,the scan driver wiring area has a width of approximately 0.25 mm, andthe signal line has a width of approximately 0.3 mm.

The frit 320 is formed so that its width (0.7 mm) can be overlapped withthe scan driver by a width of approximately 0.7 mm since the scan driver410 comprises an active area, a scan driver wiring area and a signalline. The frit 320 is not formed in a region of a seal of widthapproximately (1.5 mm) 430, but formed to the extent of the active areaof the scan driver. Therefore, a dead space may be reduced byapproximately 0.7 mm in the region of the seal 430. A dead space inanother side in which another scan driver is formed is also reduced, andtherefore a dead space may be reduced by the total width ofapproximately 1.4 mm in the both sides. In certain embodiments, thewidth W of the portion overlapped by the scan driver and the frit sealis about 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55,0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95 and 1.0 mm. In someembodiments, the width may be within a range defined by two of theforegoing widths.

In one embodiment, the frit 320 is formed on a buffer layer 101, a gateinsulation film 103, an interlayer insulation film 105, an overcoat 107and a metal film 108 b, which are extended together with the pixelregion 210 and sequentially formed to the extent of the non-pixel region220. The scan driver is inhibited from being damaged with the metal film108 b by reflecting a laser beam or an infrared ray in a region in whichthe scan driver is formed when the laser beam or the infrared ray isirradiated to the frit 320. The frit 320 also inhibits hydrogen, oxygenand moisture from being penetrated by encapsulating the pixel region 210and is formed to surround some region of the non-pixel region 220including the pixel region 210. A reinforcing absorbent may be furtherformed in an edge region in which the frit 320 is formed.

The frit 320 can comprise a powdery glass material, but can alsocomprise a paste. The frit 320 is melted using a laser or an infraredray. The frit 320 includes in certain embodiments a laser absorbent, anorganic binder, and/or a filler for reducing a thermal expansioncoefficient. In one embodiment, a paste glass frit 320, doped with atleast one kind of a transition metal using a screen printing ordispensing method, is applied to a height of approximately 14 to 15 mmand a width of approximately 0.6 to 0.7 mm. Moisture and/or organicbinder is removed and the frit 320 is plasticized to cure the glassfrit.

The second substrate 300 is arranged on the second substrate 200, inwhich the organic light emitting element 100 is formed, so that thesecond substrate 300 can be overlapped with some regions of the pixelregion 210 and the non-pixel region 220. The frit 320 is melted andadhered to the first substrate 200 by irradiating a laser along the frit320 in the back surface of the second substrate 300.

In one embodiment, the laser beam is irradiated at a power ofapproximately 36 to 38 W and the laser beam is translocated along thefrit 320 at a substantially constant speed. In one embodiment, the laseris scanned at a speed of 10 to 30 mm/sec, and more preferablyapproximately 20 mm/sec so as to sustain a more uniform meltingtemperature and adhesive force. The laser beam is preferably notirradiated to patterns such as a metal line on the substrate 200 of thenon-pixel region 220 corresponding to the frit 320.

In certain embodiments, the frit 320 is formed to encapsulate only apixel region 210. In other embodiments, the frit 320 is formed toencapsulate a scan drive unit 410. In these embodiments, a size of thesealing substrate 300 should be varied accordingly. In certainembodiments, frit 320 is formed in the sealing substrate 300. In otherembodiments, the frit 320 is formed in the substrate 200. A laser can beused for melting the frit 320 and then adhering it to the substrate 200,however other power sources such as an infrared ray may also be used.

As described above, embodiments of the invention are described in detailreferring to the accompanying drawings. It should be understood that theterms used in the specification and appended claims should not beconstrued as limited to general and dictionary meanings, but should beinterpreted based on the meanings and concepts corresponding totechnical aspects of the invention on the basis of the principle thatthe inventor is allowed to define terms appropriately for the bestexplanation. Therefore, the description herein is simply an example forthe purpose of illustrations only, and is not intended to limit thescope of the invention. It should be understood that other equivalentsand modifications could be made thereto without departing from thespirit and scope of the invention.

1. An organic light emitting device comprising: a first substratedefining a pixel region and a non-pixel region; an array of organiclight emitting pixels formed over the pixel region of the firstsubstrate; a second substrate placed over the first substrate, the arraybeing interposed between the first and second substrates; a frit sealcomprising a plurality of elongated segments interposed between thefirst and second substrates, the plurality of elongated segments incombination surrounding the array such that the array is encapsulated bythe first substrate, the second substrate and the frit seal, theplurality of elongated segments comprising a first elongated segmentelongated generally in a first direction; and a scan driver formed overthe non-pixel region of the first substrate, wherein the scan driveroverlaps with the first elongated segment when viewed in a seconddirection from the first or second substrate, wherein the shortestdistance between the first and second substrates is defined in thesecond direction.
 2. The device of claim 1, wherein the first elongatedsegment substantially eclipses the scan driver.
 3. The device of claim1, wherein the scan driver substantially eclipses the first elongatedsegment.
 4. The device of claim 1, wherein the frit does not overlap thescan driver in its entirety.
 5. The device of claim 1, wherein the scandriver extends generally in the first direction parallel to the firstelongated segment.
 6. The device of claim 5, wherein the first elongatedsegment overlaps a portion of the scan driver facing the array.
 7. Thedevice of claim 6, wherein the portion is elongated generally in thefirst direction.
 8. The device of claim 6, wherein the portion has awidth defined in a third direction perpendicular to the first and seconddirections, and wherein the width is from about 0.05 mm to about 0.5 mm.9. The device of claim 1, wherein the scan driver has a width defined ina third direction perpendicular to the first and second directions,wherein the width is from about 0.2 mm to about 1.5 mm.
 10. The deviceof claim 1, wherein the scan driver comprises a wiring area, and whereinthe first elongated segment overlaps with the wiring area when viewed inthe second direction.
 11. The device of claim 1, wherein the scan drivercomprises an active area, and wherein the first elongated segmentoverlaps with the active area when viewed in the second direction. 12.The device of claim 1, further comprising an electrically conductivelayer formed between the first elongated segment and the scan driver.13. The device of claim 12, wherein the array comprises an anode, andwherein the electrically conductive layer is deposited simultaneouslywith the anode.
 14. The device of claim 12, wherein the electricallyconductive layer is reflective with respect to a laser beam or infraredbeam.
 15. The device of claim 1, further comprising a planarizationlayer formed between the first substrate and the frit, and wherein thescan driver is substantially buried in the planarization layer.
 16. Thedevice of claim 1, wherein the scan driver comprises an integratedcircuit comprising a thin film transistor.
 17. The device of claim 1,wherein the frit seal comprises one or more materials selected from thegroup consisting of magnesium oxide (MgO), calcium oxide (CaO), bariumoxide (BaO), lithium oxide (Li₂O), sodium oxide (Na₂O), potassium oxide(K₂O), boron oxide (B₂O₃), vanadium oxide (V₂O₅), zinc oxide (ZnO),tellurium oxide (TeO₂), aluminum oxide (Al₂O₃), silicon dioxide (SiO₂),lead oxide (PbO), tin oxide (SnO), phosphorous oxide (P₂O₅), rutheniumoxide (Ru₂O), rubidium oxide (Rb₂O), rhodium oxide (Rh₂O), ferrite oxide(Fe₂O₃), copper oxide (CuO), titanium oxide (TiO₂), tungsten oxide(WO₃), bismuth oxide (Bi₂O₃), antimony oxide (Sb₂O₃), lead-borate glass,tin-phosphate glass, vanadate glass, and borosilicate.
 18. A method ofmaking an organic light emitting device, the method comprising:providing a first substrate defining a pixel region and a non-pixelregion; forming an array of organic light emitting pixels over the pixelregion of the first substrate; forming a scan driver over the non-pixelregion of the first substrate; arranging a second substrate over thefirst substrate such that the array being interposed between the firstand second substrates; interposing a frit comprising a plurality ofelongated segments between the first substrate and second substrate, theplurality of elongated segments in combination surrounding the array,and the plurality of elongated segments comprising a first elongatedsegment elongated generally in a first direction; and wherein the scandriver overlaps with the first elongated segment when viewed in a seconddirection from the first or second substrate, wherein the shortestdistance between the first and second substrates is defined in thesecond direction.
 19. The method of claim 18, wherein the firstelongated segment substantially eclipses the scan driver.
 20. The methodof claim 18, wherein an electrically conductive layer is interposedbetween the first elongated segment and the scan driver.